[PATCH net] net: dsa: Do not override PHY interface if already configured

[PATCH net] net: dsa: Do not override PHY interface if already configured

[Florian Fainelli]

In case we need to divert reads/writes using the slave MII bus, we may have
already fetched a valid PHY interface property from Device Tree, and that
mode is used by the PHY driver to make configuration decisions.

If we could not fetch the "phy-mode" property, we will assign p->phy_interface
to PHY_INTERFACE_MODE_NA, such that we can actually check for that condition as
to whether or not we should override the interface value.

Fixes: 19334920eaf7 ("net: dsa: Set valid phy interface type")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
Hi Guenter,

Could you verify this does not break what you were trying to fix with your change?
I am fairly confident this will not because for "PHYs" built-into the switch port
we will not be able to fetch a "phy-mode" property from DT, so we will use
PHY_INTERFACE_MODE_NA, but here, we will re-assign them to PHY_INTERFACE_MODE_GMII
as before.

Thanks!

 net/dsa/slave.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index 0917123790ea..35c47ddd04f0 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -756,7 +756,8 @@ static int dsa_slave_phy_connect(struct dsa_slave_priv *p,
 		return -ENODEV;
 
 	/* Use already configured phy mode */
-	p->phy_interface = p->phy->interface;
+	if (p->phy_interface == PHY_INTERFACE_MODE_NA)
+		p->phy_interface = p->phy->interface;
 	phy_connect_direct(slave_dev, p->phy, dsa_slave_adjust_link,
 			   p->phy_interface);
 
-- 
2.1.0

Re: [PATCH net] net: dsa: Do not override PHY interface if already configured

[David Miller]

From: Florian Fainelli <f.fainelli@gmail.com>
Date: Sat,  8 Aug 2015 12:58:57 -0700

> In case we need to divert reads/writes using the slave MII bus, we may have
> already fetched a valid PHY interface property from Device Tree, and that
> mode is used by the PHY driver to make configuration decisions.
> 
> If we could not fetch the "phy-mode" property, we will assign p->phy_interface
> to PHY_INTERFACE_MODE_NA, such that we can actually check for that condition as
> to whether or not we should override the interface value.
> 
> Fixes: 19334920eaf7 ("net: dsa: Set valid phy interface type")
> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
> ---
> Hi Guenter,
> 
> Could you verify this does not break what you were trying to fix with your change?
> I am fairly confident this will not because for "PHYs" built-into the switch port
> we will not be able to fetch a "phy-mode" property from DT, so we will use
> PHY_INTERFACE_MODE_NA, but here, we will re-assign them to PHY_INTERFACE_MODE_GMII
> as before.

I was trying to wait for Guenter's testing before applying this, but it's been some
time already and it makes no sense to wait any longer.

Applied to 'net', thanks Florian.

Re: [PATCH net] net: dsa: Do not override PHY interface if already configured

[Florian Fainelli]

On 12/08/15 14:30, David Miller wrote:
> From: Florian Fainelli <f.fainelli@gmail.com>
> Date: Sat,  8 Aug 2015 12:58:57 -0700
> 
>> In case we need to divert reads/writes using the slave MII bus, we may have
>> already fetched a valid PHY interface property from Device Tree, and that
>> mode is used by the PHY driver to make configuration decisions.
>>
>> If we could not fetch the "phy-mode" property, we will assign p->phy_interface
>> to PHY_INTERFACE_MODE_NA, such that we can actually check for that condition as
>> to whether or not we should override the interface value.
>>
>> Fixes: 19334920eaf7 ("net: dsa: Set valid phy interface type")
>> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
>> ---
>> Hi Guenter,
>>
>> Could you verify this does not break what you were trying to fix with your change?
>> I am fairly confident this will not because for "PHYs" built-into the switch port
>> we will not be able to fetch a "phy-mode" property from DT, so we will use
>> PHY_INTERFACE_MODE_NA, but here, we will re-assign them to PHY_INTERFACE_MODE_GMII
>> as before.
> 
> I was trying to wait for Guenter's testing before applying this, but it's been some
> time already and it makes no sense to wait any longer.

I should be able to verify this myself in the future since I just setup
a Marvell/DSA switch device here for testing.

> 
> Applied to 'net', thanks Florian.

Could you also schedule this for -stable, at least 4.1 is affected by
this change, thank you!
-- 
Florian

Re: [PATCH net] net: dsa: Do not override PHY interface if already configured

[David Miller]

From: Florian Fainelli <f.fainelli@gmail.com>
Date: Wed, 12 Aug 2015 14:34:12 -0700

> On 12/08/15 14:30, David Miller wrote:
>> Applied to 'net', thanks Florian.
> 
> Could you also schedule this for -stable, at least 4.1 is affected by
> this change, thank you!

Done, thanks.

Re: [PATCH net] net: dsa: Do not override PHY interface if already configured

[Guenter Roeck]

On Wed, Aug 12, 2015 at 02:30:35PM -0700, David Miller wrote:
> From: Florian Fainelli <f.fainelli@gmail.com>
> Date: Sat,  8 Aug 2015 12:58:57 -0700
> 
> > In case we need to divert reads/writes using the slave MII bus, we may have
> > already fetched a valid PHY interface property from Device Tree, and that
> > mode is used by the PHY driver to make configuration decisions.
> > 
> > If we could not fetch the "phy-mode" property, we will assign p->phy_interface
> > to PHY_INTERFACE_MODE_NA, such that we can actually check for that condition as
> > to whether or not we should override the interface value.
> > 
> > Fixes: 19334920eaf7 ("net: dsa: Set valid phy interface type")
> > Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
> > ---
> > Hi Guenter,
> > 
> > Could you verify this does not break what you were trying to fix with your change?
> > I am fairly confident this will not because for "PHYs" built-into the switch port
> > we will not be able to fetch a "phy-mode" property from DT, so we will use
> > PHY_INTERFACE_MODE_NA, but here, we will re-assign them to PHY_INTERFACE_MODE_GMII
> > as before.
> 
> I was trying to wait for Guenter's testing before applying this, but it's been some
> time already and it makes no sense to wait any longer.
> 
No problem. I am overloaded, and my test system is currently down, so it will
take a while. If I find a problem I'll discuss with Florian and send a follow-up
patch if needed.

Guenter